Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
Remixed from a drawing in 'Jezebel's Daughter', Wilkie Collins 1880
Source Firkin
Prismatic Rounded Squares Grid 3 No Background
Source GDJ
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
Farmer could be some sort of fabric pattern, with a hint of green.
Source Fabian Schultz
Greyscale version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Derived from a drawing in 'The Murmur of the Shells', Samuel Cowen, 1879.
Source Firkin
Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A free web background image with a seamless concrete-like texture and an Indian-red color.
Source V. Hartikainen
Dark blue concrete wall with some small dust spots.
Source Atle Mo
The classic notebook paper with horizontal stripes.
Source Are Sundnes
Same classic 45-degree pattern, dark version.
Source Luke McDonald
You know I love paper patterns. Here is one from Stephen. Say thank you!
Source Stephen Gilbert
Drawn in Paint.net and vectorised in Vector Magic
Source Firkin
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
A seamless pattern made from the gold Penrose triangle by GDJ and the two remixes
Source Firkin
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein